In a photovoltaic (“PV”) system, solar panels are organized into an array of strings. Typically, each string contains the same number of panels as all other strings. The strings are connected together in parallel to produce the desired voltage and current necessary for efficient DC to AC conversion.
In any large array of identical elements, single points of failure are common and must be detected so that corrective action can be taken to insure that all elements in the array are producing power. In addition to sudden failures, performance may degrade for a variety of reasons, such as soiling or a partial panel failure. One common solution to this problem is to measure the current produced by each string. However, for large commercial and utility scale arrays containing thousands of solar panels, individually measuring the current of each string requires a significant capital investment in hardware and related construction costs. Thus, there is a need for a system and method for detecting failures and performance degradation in a photovoltaic array that reduces the upfront capital investment while providing comparable accuracy.